From: <gregkh@linuxfoundation.org>
To: dan.j.williams@intel.com, dave.jiang@intel.com, stable@vger.kernel.org
Cc: <stable@vger.kernel.org>
Subject: FAILED: patch "[PATCH] cxl/pmem: Fix nvdimm registration races" failed to apply to 5.15-stable tree
Date: Tue, 07 Mar 2023 10:34:45 +0100 [thread overview]
Message-ID: <1678181685158238@kroah.com> (raw)
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x f57aec443c24d2e8e1f3b5b4856aea12ddda4254
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '1678181685158238@kroah.com' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
f57aec443c24 ("cxl/pmem: Fix nvdimm registration races")
4a0079bc7aae ("nvdimm: Replace lockdep_mutex with local lock classes")
3b6c6c039707 ("nvdimm/region: Delete nd_blk_region infrastructure")
84bd3690bf54 ("nvdimm/namespace: Delete nd_namespace_blk")
fadc38a6672a ("nvdimm/namespace: Delete blk namespace consideration in shared paths")
d9d290d7e659 ("nvdimm/region: Fix default alignment for small regions")
60b8f17215de ("cxl/pmem: Translate NVDIMM label commands to CXL label commands")
12f3856ad42d ("cxl/mbox: Add exclusive kernel command support")
ff56ab9e164d ("cxl/mbox: Convert 'enabled_cmds' to DECLARE_BITMAP")
4faf31b43468 ("cxl/mbox: Move mailbox and other non-PCI specific infrastructure to the core")
4cb35f1ca05a ("cxl/pci: Drop idr.h")
b64955a92929 ("cxl/mbox: Introduce the mbox_send operation")
13e7749d06b3 ("cxl/pci: Clean up cxl_mem_get_partition_info()")
99e222a5f1b6 ("cxl/pci: Make 'struct cxl_mem' device type generic")
5af96835e4da ("libnvdimm/labels: Introduce CXL labels")
540ccaa2e4dd ("libnvdimm/label: Define CXL region labels")
42e192aa9891 ("libnvdimm/labels: Introduce the concept of multi-range namespace labels")
8172db92527c ("libnvdimm/label: Add a helper for nlabel validation")
d1c6e08e7503 ("libnvdimm/labels: Add uuid helpers")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f57aec443c24d2e8e1f3b5b4856aea12ddda4254 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams@intel.com>
Date: Mon, 13 Feb 2023 17:01:05 -0800
Subject: [PATCH] cxl/pmem: Fix nvdimm registration races
A loop of the form:
while true; do modprobe cxl_pci; modprobe -r cxl_pci; done
...fails with the following crash signature:
BUG: kernel NULL pointer dereference, address: 0000000000000040
[..]
RIP: 0010:cxl_internal_send_cmd+0x5/0xb0 [cxl_core]
[..]
Call Trace:
<TASK>
cxl_pmem_ctl+0x121/0x240 [cxl_pmem]
nvdimm_get_config_data+0xd6/0x1a0 [libnvdimm]
nd_label_data_init+0x135/0x7e0 [libnvdimm]
nvdimm_probe+0xd6/0x1c0 [libnvdimm]
nvdimm_bus_probe+0x7a/0x1e0 [libnvdimm]
really_probe+0xde/0x380
__driver_probe_device+0x78/0x170
driver_probe_device+0x1f/0x90
__device_attach_driver+0x85/0x110
bus_for_each_drv+0x7d/0xc0
__device_attach+0xb4/0x1e0
bus_probe_device+0x9f/0xc0
device_add+0x445/0x9c0
nd_async_device_register+0xe/0x40 [libnvdimm]
async_run_entry_fn+0x30/0x130
...namely that the bottom half of async nvdimm device registration runs
after the CXL has already torn down the context that cxl_pmem_ctl()
needs. Unlike the ACPI NFIT case that benefits from launching multiple
nvdimm device registrations in parallel from those listed in the table,
CXL is already marked PROBE_PREFER_ASYNCHRONOUS. So provide for a
synchronous registration path to preclude this scenario.
Fixes: 21083f51521f ("cxl/pmem: Register 'pmem' / cxl_nvdimm devices")
Cc: <stable@vger.kernel.org>
Reported-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c
index 08bbbac9a6d0..71cfa1fdf902 100644
--- a/drivers/cxl/pmem.c
+++ b/drivers/cxl/pmem.c
@@ -76,6 +76,7 @@ static int cxl_nvdimm_probe(struct device *dev)
return rc;
set_bit(NDD_LABELING, &flags);
+ set_bit(NDD_REGISTER_SYNC, &flags);
set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask);
set_bit(ND_CMD_GET_CONFIG_DATA, &cmd_mask);
set_bit(ND_CMD_SET_CONFIG_DATA, &cmd_mask);
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index b38d0355b0ac..5ad49056921b 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -508,7 +508,7 @@ static void nd_async_device_unregister(void *d, async_cookie_t cookie)
put_device(dev);
}
-void nd_device_register(struct device *dev)
+static void __nd_device_register(struct device *dev, bool sync)
{
if (!dev)
return;
@@ -531,11 +531,24 @@ void nd_device_register(struct device *dev)
}
get_device(dev);
- async_schedule_dev_domain(nd_async_device_register, dev,
- &nd_async_domain);
+ if (sync)
+ nd_async_device_register(dev, 0);
+ else
+ async_schedule_dev_domain(nd_async_device_register, dev,
+ &nd_async_domain);
+}
+
+void nd_device_register(struct device *dev)
+{
+ __nd_device_register(dev, false);
}
EXPORT_SYMBOL(nd_device_register);
+void nd_device_register_sync(struct device *dev)
+{
+ __nd_device_register(dev, true);
+}
+
void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
{
bool killed;
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 1fc081dcf631..6d3b03a9fa02 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -624,7 +624,10 @@ struct nvdimm *__nvdimm_create(struct nvdimm_bus *nvdimm_bus,
nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER);
device_initialize(dev);
lockdep_set_class(&dev->mutex, &nvdimm_key);
- nd_device_register(dev);
+ if (test_bit(NDD_REGISTER_SYNC, &flags))
+ nd_device_register_sync(dev);
+ else
+ nd_device_register(dev);
return nvdimm;
}
diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index cc86ee09d7c0..845408f10655 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -107,6 +107,7 @@ int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus);
void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus);
void nd_synchronize(void);
void nd_device_register(struct device *dev);
+void nd_device_register_sync(struct device *dev);
struct nd_label_id;
char *nd_label_gen_id(struct nd_label_id *label_id, const uuid_t *uuid,
u32 flags);
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index af38252ad704..e772aae71843 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -41,6 +41,9 @@ enum {
*/
NDD_INCOHERENT = 7,
+ /* dimm provider wants synchronous registration by __nvdimm_create() */
+ NDD_REGISTER_SYNC = 8,
+
/* need to set a limit somewhere, but yes, this is likely overkill */
ND_IOCTL_MAX_BUFLEN = SZ_4M,
ND_CMD_MAX_ELEM = 5,
reply other threads:[~2023-03-07 9:35 UTC|newest]
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